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Biomedical subjects

G Pohl

Publications and source records attributed to G Pohl.

At least 37 records · Page 2Linked to original sources
PubMed1990

Pharmacokinetics and coronary thrombolytic properties of two human tissue-type plasminogen activator variants lacking the finger-like, growth factor-like, and first kringle domains (amino acids 6-173) in a canine model.

The pharmacokinetics and thrombolytic properties of two variants of recombinant human tissue-type plasminogen activator (rt-PA) were studied in dogs with a copper coil induced thrombosis of the left anterior descending coronary artery. The first variant, rt-PA-delta FEK1-Gln184, lacked amino acids 6 to 173 [comprising the fibronectin finger-like (F), the epidermal growth factor-like (E), and the first kringle (K1) domains] and had the glycosylated Asn184 mutagenized to Gln. The second variant, rt-PA-delta FEK1-Gln184, Val277, had in addition Lys277 mutagenized to Val. Injection of 0.25, 0.50, or 1.0 mg/kg of rt-PA in groups of three dogs caused reflow in six of nine dogs, within 18 +/- 15 min (mean +/- SD), but was associated with reocclusion within 2 h in all animals. Injection of 0.125, 0.25, or 0.50 mg/kg of rt-PA-delta FEK1-Gln184 caused reflow in all of nine dogs, within 17 +/- 23 min, with persistent patency in four animals (p = 0.02 vs. rt-PA). Bolus injection of 4:1 mixtures of rt-PA-delta FEK1-Gln184 and rt-PA in total amounts of 0.125, 0.25, or 0.50 mg/kg resulted in reflow in eight of nine dogs within 25 +/- 21 min with persistent patency in seven (p = 0.003 vs. rt-PA, p = 0.25 vs. rt-PA-delta FEK1-Gln184 alone). Injection of 0.25, 0.50, or 1.0 mg/kg of rt-PA-delta FEK1-Gln184, Val277 produced reperfusion in six of nine dogs, within 27 +/- 26 min, with persistent patency in three (p = 0.59 vs. rt-PA and p = 0.23 vs. rt-PA-delta FEK1-Gln184).(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1990

[Mammaplasty. A component of the combined therapy program in the treatment of malignant breast diseases].

Breast reconstruction following mastectomy is a part of programme in rehabilitation. The type of reconstruction is determined by the local defect. 1. The advanced skin technique with or without skin expander and silicone breast implant is in this time the most used procedure. 2. If needed skin the thoracoepigastric flap is used. 3. If additional skin and muscular cover is needed, the latissimus dorsi flap, lower m. rectus abdominis flap, the upper m. rectus abdominis flap are used or free flap.

Breast↗
PubMed1990

[The effect of hand-reduction interventions on hand function].

The indication of finger- and transmetacarpal amputation cannot be standardized. Some diagrams can give orientation. The procedure to be used has to be determined from case to case dependent on age, profession, intelligence and readiness to postoperative cooperation. Operations with transmetacarpal amputation have not satisfactory results in function of the hand.

Adult↗
PubMed1989

[Mammographic findings following reduction mammaplasty].

Clinical and mammographic follow-up checks were made on 64 women with a record of breast reduction surgery. Mammographic changes, such as thickened skin, distortion of nipples as well as thickening and dislocation of parenchymal tissue, can be relatively easily differentiated from malignant changes, primarily in cases in which such changes are symmetrical and in which case histories and earlier clinical findings are known. Bilateral calcifications in most cases are caused by calcified fat necrosis.

Adolescent↗
PubMed1988

Human tissue-type plasminogen activator synthesized by using a baculovirus vector in insect cells compared with human plasminogen activator produced in mouse cells.

A cDNA fragment encoding the human tissue-type plasminogen activator was inserted into the baculovirus Autographa californica nuclear polyhedrosis virus downstream from the polyhedrin promoter. The induction kinetics of t-PA was followed, after infection of Spodoptera frugiperda cells, at both mRNA and protein levels. Fibrinolytically active plasminogen activator accumulated in the culture medium and reached 2.5 micrograms/ml after 120 h. The protein was compared with recombinant plasminogen activator produced in mouse cells and was found to be slightly smaller. This difference in size was found to be caused by N-linked oligosaccharides which are shorter in the recombinant activator obtained from insect cells. The molecules produced in such cells contain at least two different types of N-linked glycans, since only one out of three oligosaccharides is sensitive to endoglycosidase H. However, all glycan structures bind strongly to concanavalin A-Sepharose.

Animals↗
PubMed1988

[Terminology in plastic and reconstructive surgery].

Precise definition is essential to diagnosis of diseases, therapeutic approaches, including surgical methods, and techniques. Terminological confusion may create insecurity among those seeking advice and may lead to erroneous consequences. The scope of Plastic and Reconstructive Surgery is outlined in this paper, and some major terms are interpreted.

Humans↗
PubMed1988

[Results following reduction mammoplasties. A comparison of selected surgical procedures].

Lactation-retaining reducing mammoplasty was performed on 144 cases for macromastia, with 54 of them being carried out by the Biesenberger/Gelbke method and 90 according to the procedure by Strömbeck. Complications due to wound healing disorders occurred only to eleven in 98 mammae (separate evaluation) treated by the Strömbeck procedure but affected every second patient operated on by the Biesenberger/Gelbke method. In 14 patients postoperative capability of lactation was found to be unambiguously correlated with unimpaired wound healing. Postoperative pathological alterations in mammary glands may cause problems in differential diagnosis. Mitigation of clinico-somatic complaints was found to be obtainable from either surgical approach, depending on wound healing. Aesthetic results are the same.

Adult↗
PubMed1988

[Dupuytren's disease in advanced age. Treatment strategy and results].

The results recorded from 1,322 surgical cases of Dupuytren's contracture of all severities have shown that successful treatment is possible even of patients in advanced age. The concept of surgery and treatment on an outpatient basis was applied to 86.6 per cent of the above cases, with local anaesthesia being used, and has proved to be absolutely adequate, provided high-continuity care by surgeons experienced in hand surgery. Results, prerequisites, and advantages are described in a differentiated manner.

Adolescent↗
PubMed1987

Isolation and characterization of three different carbohydrate chains from melanoma tissue plasminogen activator.

Electrophoretic analysis of endoglycosidase-treated tissue plasminogen activator obtained from human melanoma cells showed that the heterogeneity observed for the protein in these preparations is caused by an N-glycosidically linked N-acetyllactosamine type of carbohydrate chain which is present in about 50% of the molecules. An oligomannose type and an N-acetyllactosamine type of glycan is present in all molecules. Three glycopeptides were isolated and characterized by 1H-NMR, sugar determination, methylation analysis and amino acid determination. The exact attachment site for each of the three glycans could be deduced from the amino acid compositions of the glycopeptides. Asn-117 carries the oligomannose type of glycan, the structure of which was completely determined. Asn-184 is the site where the presence or absence of a biantennary N-acetyllactosamine type of glycan causes the size heterogeneity. The third N-glycosylation site, Asn-448, was found to carry a triantennary or tetraantennary N-acetyllactosamine type of carbohydrate chain.

Amino Acids↗
PubMed1987

Expression of human insulin-like growth factor I in bacteria: use of optimized gene fusion vectors to facilitate protein purification.

Several fusions between the gene for human insulin-like growth factor I (IGF-I) and the genes for different IgG-binding fragments of staphylococcal protein A were assembled and compared regarding expression, secretion, and purification of the peptide hormone. After IgG affinity purification of the fusion proteins from the growth medium of Staphylococcus aureus or Escherichia coli, native IGF-I was released by cleavage of an Asn-Gly peptide bond with hydroxylamine. An optimized expression system based on a modified synthetic IgG-binding domain (z), resistant to hydroxylamine, gave the highest yield of fusion protein. After cleavage, the hormone could be separated from the IgG-binding moiety and from noncleaved fusion protein by a second passage through the IgG affinity column. The biological activity and the purity of the IGF-I obtained were confirmed by a radioreceptor assay, N-terminal sequence analysis, polyacrylamide gel electrophoresis, isoelectric focusing, and high-performance liquid chromatography.

Cloning, Molecular↗
PubMed1987

[Surgical therapy in advanced (exulcerated) breast cancer].

Surgical treatment of 39 cases of advanced (exulcerated) mammary carcinoma in stages III b and IV is reported in this paper. Rotter-Halsted operations were performed on 13 patients, while simple or modified radical mastectomy was applied to 26. Thoraco-epigastric flaps had to be used for plastic coverage of larger soft tissue defects in the thoracic wall in nine cases. Plastic surgical repair is supported by the authors in cases in which the quality of life can thus be improved.

Adult↗
PubMed1986

Porcine tissue plasminogen activator. Immunoaffinity purification, structural properties and glycosylation pattern.

Tissue plasminogen activator was purified in high yield from pig heart by immunoaffinity chromatography and characterized by analysis of the glycosylation pattern and the N-terminal amino acid sequence. Comparisons with the human enzyme reveals residue exchanges in the A-chain at positions 3 (porcine Arg/human Gln) and 5 (Thr/Ile), and in the B-chain at positions 6 (Tyr/Phe), 10 (Thr/Ala) and 20 (Val/Ala). The glycosylation pattern for the porcine activator was determined by endoglycosidase treatment followed by gel electrophoresis. The A-chain contains a single high-mannose type of N-linked glycan structure and the B-chain contains a complex type of oligosaccharide. A similar but not identical pattern has been observed for the human activator, purified from melanoma cells.

Amino Acid Sequence↗
PubMed1986

Proteolytically induced variations in the enzymatic properties of tissue plasminogen activator. Activations, inactivations and reactivations.

Tissue plasminogen activator was treated with Sepharose-bound trypsin or chymotrypsin. Trypsin rapidly converted the one-chain activator to the two-chain form. This caused a marked increase in the amidolytic activity, while plasminogen activation initially increased but then decreased again. SDS/polyacrylamide gel electrophoresis in combination with [3H]diisopropylfluorophosphate active-site labeling revealed that after the conversion to the two-chain activator a minor cleavage occurred in the B chain, while the A chain was substantially degraded. Chymotrypsin caused a marked decrease in both amidolytic activity and plasminogen activation. SDS/polyacrylamide gel electrophoresis under reducing conditions revealed that two pairs of new bands had appeared, with Mr or about 50,000/52,000 and 17,000/20,000 respectively. N-terminal sequence analysis identified cleavage sites at peptide bonds 420-421 and 423-424. These bonds are located in a region of the activator which is homologues to the segments of trypsin and chymotrypsin, where autocatalytic cleavages occur during their activations. However, treatment of two-chain activator with chymotrypsin had markedly less effect on plasminogen activation and amidolytic activity. By treatment of samples of chymotrypsin-digested one-chain activator with plasmin, amidolytic activity could be largely restored. Thus, chymotrypsin may, by cleaving bonds 420-421 and 423-424, convert the active one-chain activator into an 'inactive' zymogen, which is again 'activated' by plasmin cleavage.

Amino Acid Sequence↗
PubMed1985

Purification and some properties of carbonic anhydrase from bovine skeletal muscle.

Procedures for the purification of bovine muscle carbonic anhydrase (isoenzyme III) are described. The purified enzyme has a molecular weight near 29,000 and contains one Zn2+ ion per molecule. The sedimentation coefficient, s(0)20,w, is 2.8 X 10(-13) s, the isoelectric pH is 8.5, and A280(0.1%) = 2.07 cm-1. The CO2 hydration activity, expressed as kcat/Km, is about 1.5% of that of human isoenzyme I (or B) and about 0.3% of that of human isoenzyme II (or C) at pH 8 and 25 degrees C. The activity is nearly independent of pH between pH 6.0 and 8.6. The muscle enzyme is weakly inhibited by the sulfonamide inhibitor, acetazolamide, whereas some anions, particularly sulfide and cyanate, are efficient inhibitors. Bovine carbonic anhydrase III contains five thiol groups, two of which react readily with Ellman's reagent without effect on the catalytic activity. A reinvestigation of the amino acid sequences of cysteine-containing tryptic peptides has shown that cysteine residues occur at sequence positions 66, 183, 188, 203, and 206.

Amino Acid Sequence↗
PubMed1984

Tissue plasminogen activator: peptide analyses confirm an indirectly derived amino acid sequence, identify the active site serine residue, establish glycosylation sites, and localize variant differences.

Tissue plasminogen activator, separated into variants I and II (differing in Mr by 2000-3000), was reduced and [14C]carboxymethylated. Fragments from cleavages with enzymes and cyanogen bromide (CNBr) were separated by reverse-phase high-performance liquid chromatography and subjected to sequence degradations. All seven CNBr fragments were purified and found to be compatible with the cDNA-derived amino acid sequence [Pennica, D., Holmes, W. E., Kohr, W. J., Harkins, R. N., Vehar, G. A., Ward, C. A., Bennett, W. F., Ylverton, E., Seeburg, P. H., Heynecker, H. L., Goeddel, D. V., & Collen, D. (1983) Nature (London) 301, 214-221]. Chemical characterization of 93% of the 527 residues recovered in 50 peptides confirmed the indirectly deduced primary structure of the protein. The tryptic peptide patterns from the two variants were found to differ for one peptide (T15). Since carbohydrate was present in this peptide for variant I and since a marked difference in chromatographic behavior for T15 was observed in variant II, we conclude that carbohydrate differences in this peptide (i.e., Asn-184 in the numbering system of the cDNA-derived amino acid sequence) are the explanation for the size differences between variants I and II. Carbohydrate was also found at two other positions in the protein, corresponding to Asn-117 and Asn-448. However, a fourth potential glycosylation site, Asn-218, is apparently not utilized for carbohydrate attachment. The enzyme is inactivated by diisopropyl phosphorofluoridate, which covalently modifies the serine residue corresponding to position 478, identifying this as the active site serine residue.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1984

Differences between uterine and melanoma forms of tissue plasminogen activator.

Tissue plasminogen activator purified from human uterine tissue exhibits differences in N-terminal starting positions in relation to the melanoma cell plasminogen activator usually studied. A new starting position is compatible with an additional N-terminal processing apart from those already known. Like the melanoma activator, the uterine activator was found to yield protein chains starting at either of two positions. One of these was identical between uterine and melanoma activators, whereas the other was unique in each case. The most abundant starting position for the uterine preparation was at a valine residue, apparently from cleavage of a Gln-Val bond, and corresponding to Val-7 of the longest form of the melanoma activator chain.

Amino Acid Sequence↗